Once again, after a terror attack, Americans face a debate over how to treat a suspect. The question has come up again and again since the 9/11 attacks.

GREENE: In the years before those attacks in 2001, accused terrorists were generally treated as criminal defendants. Since those attacks, some officials and advocates have pressed to classify many suspects differently.

INSKEEP: Now that debate returns with Dzhokhar Tsarnaev, who's hospitalized after being found hiding in a boat on Friday night. At issue here is whether he should be questioned as an enemy combatant.

NPR's Tovia Smith reports.

TOVIA SMITH, BYLINE: As Tsarnaev has been lying in his hospital bed surrounded by heavy security, a special team of interrogators have been eagerly awaiting to get at him. From the moment he was captured, U.S. Attorney Carmen Ortiz said interrogators would start as soon as possible, without stopping to advise him he has the right to remain silent.

CARMEN ORTIZ: There is a public safety exemption in cases of national security and potential charges involving acts of terrorism. And so the government has that opportunity right now.

SMITH: But that exemption is usually limited to 48 hours. And while there may be some wiggle room, and some discretion as to when the clock starts running, prosecutors would still be limited both in time and scope. For example, former federal judge and now Harvard law professor Nancy Gertner says they could only interrogate him about imminent danger.

NANCY GERTNER: If he were questioned about where bombs were planted now, that would clearly fit within the exception. But if they use this occasion to debrief him about why his brother went to Russia when he did - you know, things having to do with the background of the case - that would be unjustified.

SMITH: It's why some want see Tsarnaev not treated as a criminal defendant but rather held as a military detainee.

REPRESENTATIVE PETER KING: I believe he should be treated as enemy combatant for the purpose of interrogation.

SMITH: Speaking on Fox News yesterday, GOP Congressman Pete King argued that Tsarnaev is not a common criminal and authorities should have more leeway to try to get at what he knows.

KING: But right now he's really one of the only links we have as far as any Chechen involvement in the al-Qaida movement, in the overall Islamist movement. And we don't know, are there other conspirators out there? Where do they get their radicalization? Are there mosques, imams we should be looking at? Who did his brother meet with when he was in Russia and Chechnya? The battlefield is now in the United States, so I believe he is an enemy combatant.

DAVID CLIFFORD: I have no problem with that whatsoever.

SMITH: In Boston, it's not hard to find folks all for using whatever it takes, like David Clifford, who came from Maine to a makeshift memorial to the victims of the bombing.

CLIFFORD: You know, the son of (bleep) put a bomb right next to a little kid. I mean how evil is that? No, we need to send a message. This should not happen. We shall not tolerate it.

SMITH: But others say treating Tsarnaev as an enemy combatant would be not only be wrong, but also would send exactly the wrong message.

GERTNER: It's terribly important to make it clear that we don't create, carve out special categories when the crime is particularly heinous. The Constitution applies.

SMITH: Again, former Judge Nancy Gertner.

GERTNER: To take this case out of criminal justice system says we that we're creating essentially a parallel system for any case in which anyone says the word terrorism. And pretty soon the exception will begin to swallow the rule.

SMITH: Experts say it's unclear whether treating an American citizen arrested on American soil as an enemy combatant would even pass constitutional muster. Hina Shamsi, director of the of the ACLU, calls it completely unjustified.

SMITH: On a practical level, Shamsi says, there's no need for it. Indeed, if prosecutors continue to interrogate Tsarnaev without an attorney, the consequence would only be that they can't use what he says against him in court. But in this case that may not actually matter.

JOHN ASHCROFT: It doesn't appear that there is any shortage of evidence here.

SMITH: John Ashcroft, former U.S. attorney general in the George W. Bush administration, says the government may not care about Tsarnaev's own statements, given everything else they appear to have, like eyewitnesses, physical evidence and videotape.

ASHCROFT: There appears to be significant evidence that would make any statement by him or information from him superfluous.

SMITH: The prospect of Tsarnaev being endlessly grilled has got defense attorneys concerned. The Federal Public Defenders in Boston are calling for an attorney to be appointed for him, quote, ASAP.